Shares of T-Mobile US fell more than 5 percent today while Sprint stock tumbled more than 9 percent on news that a merger between the two companies in the works for 6 months may be called off.

It is reported that Sprint’s parent SoftBank is vying for semblance of control over the resulting entity. T-Mobile owner Deutsche Telekom is said to want full control of the company. Previously, it was expected that Deutsche and SoftBank would split the stakes 60/40 and that both companies’ head executives would co-chair the entity.

Sources to Reuters say that some of SoftBank’s C-suite are trying to convince chairman Masayoshi Son to rethink the deal as he would essentially lose control of one of the company’s largest assets, much less a foreign asset. CNBC’s sources contest that negotiations between the two are still active and Sprint has not definitively set an end to its participation. This is contrast to Nikkei‘s reporting.

Jules Wang is News Editor for Pocketnow and one of the hosts of the Pocketnow Weekly Podcast. He came onto the team in 2014 as an intern editing and producing videos and the podcast while he was studying journalism at Emerson College. He graduated the year after and entered into his current position at Pocketnow, full-time.